Image intensifier apparatus

Abstract

An image intensifier apparatus of this invention comprises a photocathode for converting a first optical image to corresponding photoelectrons, a microchannel plate for multiplying the photoelectrons, impressed with a voltage at both ends thereof, and a fluorescent screen for converting the photoelectrons multiplied in the microchannel plate to a second optical image, emitting the second optical image to an image pickup device. Resistance of the microchannel plate is greater than or equal to 2.8.times.10.sup.15 G.OMEGA. and less than or equal to 2.8.times.10.sup.16 G.OMEGA. per channel. Therefore, in a case that a luminance of the second optical image is smaller than or equal to saturation sensitivity of the image pickup device, the luminance of the second optical image is proportional to an illuminance of the first optical image, and in a case that the luminance of the second optical image is larger than saturation sensitivity of the image pickup device, the luminance of the second optical image is suppressed against increment of the illuminance of the first optical image. Thus, the halo phenomenon effect having a relatively large luminance is decreased.

Dependencies are inferred from the claim text.